A saw, in which the blade is pivotally attached by its base end to the top end of a handle having a U-shaped cross section and capable of being pivoted to be folded into the handle when not in use, is in widespread use as a pruning saw, a gardening saw or as a crafting saw. The present invention related to a hand saw that can be folded into a handle, as explained above (hereinafter referred to as a xe2x80x9cfolding sawxe2x80x9d).
A conventional folding saw has a straight blade pivotally attached by its base end to the top end of a straight handle. When the blade is folded into the handle, the edge is completely housed within the handle. Recently, however, as shown in FIG. 11(a), saws, in particular pruning saws, having a blade A with a concavely curved edge B and a handle C that are pivotally supported by a pivot D, have come into widespread use. Such saws having a concavely curved blade edge are generally called curved saws. A curved saw is less likely to disengage from the object to be cut, and is therefore capable of cutting the object without fail.
Accordingly, a folding saw having a blade A with a concavely curved edge B housed in a handle C, which is also concave in the same direction as the edge B, as shown in FIGS. 11(a) and 11(b), has been developed. Other variations of the folding saw include those having a blade A with a concave edge B and a straight handle. This applicant has previously invented a folding saw featuring a retractable protective cover housed inside the housing groove of the handle C, in which, when the blade A is folded, the protective cover projects out of the handle so as to cover the edge B of the blade exposing from the housing (Japanese Patent Application 2000-110794).
A folding saw combining a concavely curved edge and a straight handle has a mildly curved form when unfolded as shown in FIG. 11(a). When the blade is folded, however, a portion of the edge, in particular, the middle portion of the curved edge, is exposed as shown in FIG. 11(b). The degree of the exposure differs according to the curvature and overall length of the blade. The exposed portion poses a danger because it can injure a finger of the saw handler or damage an object while the folding saw is being carried or stored. The edge B itself can also be damaged by another object that accidentally comes into contact with it. Japanese Patent Application 2000-110794, which describes an invention by this applicant, solves the problems associated with the conventional technique described above by introducing a protective cover that protects the exposed edge part of the blade. The present invention simplifies the construction of the folding knife proposed in the above application and makes it even easier to use.
To achieve the desired objectives, the present invention introduces a protective cover 4 that can be pulled out or pushed into the housing groove 3 of the handle 2 for housing the blade 1. The protective cover 4 is pivotally movable around the top end of the handle 2. At the bottom end of the handle 2, a control lever 5 is provided. A recess portion 7 of the control lever 5 is engaged with the free end of the protective cover 4. The protective cover 4 can be inserted into, and extracted from, the housing groove 3 of the handle 2 by pivoting the control lever 5. In this way, when the blade is folded, the protective cover 4 housed in the housing groove 3 is pushed out of the housing groove 3 so as to cover the edge 1a of the blade 1 exposed outside the housing groove 3.
The control lever 5 at the bottom end of the handle 2 is pivotably attached to the bottom of the handle inside the housing groove 3 via a pivot 6, which crosses the plane of the blade 1 at a right angle. A portion of the protective cover 4 is held loosely in a recess 7 formed at one end of the control lever 5, and an activating part 5a, which is a portion of the control lever 5, extends from the periphery of the handle. A concave groove 8 is provided at a portion of the control lever 5, and the top end of the blade 1 is inserted into the concave groove 8 when folded.